Aeroplane.



H. L. COAKLEY.

AEROPLANE.

APPLICATION FILED SEPT. 4, lsu.

ZW 7./ /WW/ MC f @FENCE HENRY L. COAKLEY, 0F NEW YORK, N. Y.

AEROPLAN E.

Specification of Letters Patent.

Patented Dec. 17, 1918.

Application led September 4, 1917. Serial No. 189,697..

T 0 ZZ whom, it may concern Be it known that l, HENRY L. COAKLEY, a citizen of the Unit-ed States, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, have invented a new and Improved i-Xeroplane, of which the following is a specitication.y

`This invention relates to airplanes, and my improvements are directed more particularly to means for obtaining longitudinal, lateral and directional stability in true aeronautical combination for all natural conditions of flight in which an airplane needs to be balanced.

It is only by the intimate association of interconnected elements in the three different directions of an airplane that the factors which make for stability in any one direction will also at the same time make for stability in each of the other two direct-ions of the airplane. whereby true inherent stability can be created in an airplane.

inherent stability, as comprehended by me. consists in so devising the wings or sustentation surfaces of the airplane, in fixed relation, that the airplane will thereby be enabled to maintain its flight attitude, whether that be horizontal, or inclined as for banking, climbing or descending.

To this end l provide pairs of wings which are swept either forwardly or backwardly throughout their whole extent, so that sustentation is accorded by said wings as well directionally as longitudinally and laterally with respect to the center of gravity of the airplane. Also said wings are angled vertically. with their inner sections of greater span, forminga dihedral angle. and their outer sections, of less span,

forming each, with a central section, a re-v verse dihedral angle.

But the leading and rear edges of the wings, at each side of the airplane. are in parallel planes, which are equally inclined to the longitudinal axis of the airplane. with the leading edges of the wings throughout one side of the airplane in the same plane. Thus my improved aerofoils or supporting surfaces may be said to comprise wings which extend out laterally in opposite directions, in symmetrical, angled relation, both in plan and in elevation, the angles including a central dihedral section and outward sections of reverse dihedral.

The proportional spans of the central sections and outward sections. afford pressure areas of different extents, the central sections having greater area than the outer sections, to thus exercise substantially equal leverage about the longitudinal axis of the airplane. Therefore the pressure against a central section at one side of the airplane is equaled bythe concurrent pressure against an outer section at the opposite side, whereby said sections tend to form a balancing couple to maintain equilibrium in any atti'- tude of the airplane.

Movable aerofoils are provided for longi' tudinal, lateral and directional control of the airplane.

Other features and advantages of my said invention will hereinafter appear.

In the drawings Figure l is a plan view of an airplane embodying that form of my invention wherein swept forward wings are employed.

Fig. Q is a front elevation thereof, and Fig. is a side elevation.

Fig. el is a plan view of that embodiment of my invention having swept back wings, of arrow type.

Fig. 5 is a frontV elevation thereof, and Fig. 6 is a side elevation.

Fig. 7 is a plan view of a modification, in the form of a multiplane.

Fig. 8 is a front elevation thereofand Fig. 9 is a side elevation-Fig. 10 is a. front elevation of another modification in the form of a niultiplane.

First describing the form of my invention which appears in Figs. 1 to I have there depicted a biplane whose aerofoils are swept forward, and are angled to form the cent-ral, dihedral sections l, Q. and the outward sections 3, 4; the latter. respectively, with sections 1. 2. forming reverse dihedral angles.

The dihedral and reverse dihedral angles provided are equal in degree, and the sections constituting those angles are of like chord, but the central sections 1, 2. which are of equal span. each exceed by a like extent the span of their respectively adjacent sec tions 3, 4. Hence the areas of the central sections exceed the areas of the outer sections, and the proportional relation between these areas mustI depend upon the extent of span of the entire aerofoil supporting surface, and on the vertical location of the center of f ravity.v

Essentially, the balancing couples -provided in horizontally swept or raked wings,

which are angled as described, require that the angles ot' attack of all the sections comprising the wings be equal in degree, as measured longitudinally, throughout the span of they wings. Hence, in tront aspect, itwill be apparent that air pressures met squarely by all sections ot the aerofoil will give equal support over the entire span ot' said aerot'oil; while all deviations in pressure direction will be met b v righting couples composed of a positive section at each side ot the longitudinal axis ot the airplane; the other sections offering the less resistance as a balancing couple meets pressures exerted other than longitudinally. rThus a stable condition is established in the airplane, whether its attitude be horizontal in normal flight, or inclined as in banking for making turns, or inclined tor climbing or descent. The longitudinal angling or rake of the wings is desirable. as thereby the center ot gravity ot the airplane may be located longitudinally between vertical transverse planes bounding the chord extremities ot the aerotoil.

Movablel ailerons, as 7, 8, are respectively mounted along the rear edges of the sections 3, i, and are intended merely for the purpose of correcting variations in normal balance or load in the airplane. The airplane body or fuselage S), which may be of usual character. is shown as carrying the horizontal rudders 5, 5. and vertical rudder 6, for adjusting the airplane vertically and directionally.

r1`he aerot'oiloit' the arrow type airplane shown in Figs. l, 5 and 6, is composed of the central sections la, 2a, and outer sections 3a, 4a, these sections arranged in vertical angie larity like the sections l, Q, 3, al, but horizontally arranged to give a swept back char acter to the wings. ln their vertically angled arrangement these wings correspond with the swept forward wings previously described.

'l`he rear edges of the sections 3a, s, which are arranged in a plane inclined to the longitudinal axis of the airplane, are provided with movable ailerons, which may be rectangular. of suliicient surface area to enable thein to function as control means for adjusting the airplane vertically, laterally and directionally; whereby the use ot tail wings and vertical rudder may be dispensed with.

ln carrying out the principle of angled wings, established by my invention, in the :torni ot a multiplane machine such as indicated in the example ot Figs. 7, 8 and 9, and also in Fig'. 10. the vertically angled arrangement ot' the wings is retained as in the previously described examples. but the partielllar superposed relation of said wings equally1 enibodies the same principle ot' balance tor an airplane.

1n the examples of my invention illus- :lessees trated in the drawings 1 have shown its application to biplanes and multiplanes, but obviously the Principle involved in the production of my improved aerofoil surfaces 1s also applicable to monoplanes.

Variations may be resorted to within the spirit and scope ot' my said invention and parts thereof used without others.

1 claim:-

1. in an airplane, a supporting aerofoil comprising tixed opposite wings having central sections in dihedral relation, and outer sections in equal reverse dihedral relation with connecting central sections, whereby all the sections present the saine angle of incidence in the line of flight, to provide balancing couples, the leading edges oit' said wings throughout each side ot the airplane occupying respective planes which are 1nclined equally to the 'longitudinal axis of the airplane.

2. in an' airplane, a supporting aerot'oil con'iprisinpa fixed opposite wings having central sections in dihedral relation, and outer sections in equal reverse dihedral relation with connecting,r central sections, whereby all the sections present the same angle ot' incidence in the line of flight, to provide balancing couples, the leading edges of said wings throughout each side of the airplane occupying respective planes which are inclined equally to the longitudinal axis of the airplane, and movable members fory controlling,l the longitudinal, late al and directional movements of the airplane.

3. in an airplane, a plurality of supporting aerotoils, each comprising opposite wings having Connected sections in dihedral relation, and outer sections in equal reverse dihedral relation with connecting central sections, whereby all the sections present the same angle of incidence in the line of flight, to provide balancing couples, the leading edges or' said wings throughout each side of the airplane, occupyingrespective planes which are inclined equally to the longitudinal axis ot the airplane.

4. 1n an airplane, a plurality of supporting aerofoils, each comprising opposite wings having connected sections in dihedral relation, and outer sections in equal reverse dihedral relation with connecting central sections, whereby alltthe sections present the same angle of incidence in the line of flight, to provide balancing couples, the leading edges of said wings throughout each side of the airplane, occupying respective planes which are inclined equally to the longitudinal axis ot the airplane, and movable members tor controlling the longitudinal, lateral and directional movements of the airplane.

5. 1n an airplane. a supporting aerofoil comprising opposite wings having` connected central sections in dihedral relation. and outer sections, in equal reverse dihedral reneeaeaa lation with connecting central sections, whereby all the sections present the same angle of incidence in the line of flight, to provide 'balancing couples, the leading and rear edgesof said wings throughout each side of the airplane occupying respective parallel planes, which are inclined equally to the longitudinal axis of the airplane.

6. ln an airplane, a supporting aerofoil comprising opposite wings having connected central 'sections in dihedral relation, and outer sections, in equal reverse dihedral relation with connecting central sections, whereby all the sections present the same angle of incidence in the line of ight, to provide balancing couples, the leading and rear edges of said wings throughout each side of the airplane occupying respective parallel planes, which are inclined equally to the longitudinal axis of the airplane, and movable members for controlling the longitudinal, lateral and directional movements of the airplane.

7. lln an airplane, a plurality of supporting aerofoils, each comprising opposite wings having connected sections in dihedral relation, and outer sections in equal reverse dihedral relation with connecting central sections, whereby all the sections present the same angle of incidence in the line of flight, to prov1de balancing couples, the leading and rear edges of said wings throughout each side of the airplane occupying respective, parallel planes, which are inclined equally to `the longitudinal axis of the airplane.

8. In an airplane, a plurality of support ing aerofoils, each comprising opposite wings having connected sections in dihedral relation, and outer sections in equal reverse dihedral relation with connecting central sections, whereby all the sections present the same angle of incidence in the line of ight, to provide balancing couples, the leading and rear edges of said wings throughout each side of the airplane occupying respec`' tive, parallel planes, which are inclined equally to the longtudinal aXisof the airplane, and movable members for controlling the longitudinal, lateral and directional movements of the airplane.

9. An airplane having a supporting aerofoil whose span comprises a central dihedral portion with opposite side portions in equal, reverse dihedral relation therewith, to provide 'balancing couples, the leading edge of said aerofoil extending Out in opposite directions from its center in respective angles which each occupy a plane that is inclined to the longitudinal axis of the airplane.

In testimony whereof, I have signed'my name.

HENRY L. COAKLEY. Witness:

WHJLIAM C. J. MILLER. 

